Rolling mill drum



Feb. 25, 1964 F. J. BORON 3,122,337

ROLLING MILL DRUM Filed Aug. 7, 1961 s sheets-sheet 1 PASS LINE RO LL STAN D 24 22 K 50 :f:;i::f;:t;

IN NJ 20 7 f FIG. 2

INVENTOR. FRANK J. BORON BY ATTORN EYS Feb. 25, 1964 F. J. BORON 3,122,337

ROLLING MILL DRUM Filed Aug. 7, 1961 3 Sheets-Sheet 5 lllnul w" FIG. 6

FIGS

INVENTOR. FRANK J. BORON ATTORNEYS 3,122,337 ROLLING MELL DRUM Frank J. Boron, Elyria, Ohio, assignor to American Brake Shoe Company, New York, N.Y., a corporation of Delaware Filed Aug. 7, 1961, Ser. No. 129,777 Claims. (1. 2 .2-78.1)

This invention relates to a coiler or take-up drum that is to be used in a rolling mill of the kind wherein a steel strip is reduced in gauge by repeated reverse movements of the strip through the roll stand.

Companies that do not desire to undertake the capital investment in a large continuous strip mill sometimes resort to what is known as a reversing mill installation wherein a steel strip is rolled in repeated reverse paths through the roll stand. Such an operation requires a furnace at each side of the roll stand having a coiler drum therein on which the strip undergoing rolling will be wound and unwound as an incident to effecting the rolling operation in reverse paths. Thus, the strip undergoing rolling will be supplied or unwound from a coiler drum in the furnace at one side of the roll stand, and the free end of this strip will be advanced through the roll stand and guided toward the other coiler drum where it will be gradually wound up. When the supply drum is exhausted, the path through the roll stand is reversed automatically. Repeated operations of this kind are effective ultimately to reduce the strip to the desired thickness, eliminating the need for a long line of successive roil stands.

The coiler drum must be capable of withstanding a great deal of mechanical abuse because the free end of the strip strikes the coiler drum with a great deal of momentum. Thus, the drum is stationary as the oncoming end of the strip approaches it. The strip is to be slammed into a slot in the stationary coiler drum, and the coiler drum is then to be accelerated to a speed of ten to fifteen miles per hour in a matter of seconds. The consequent shock has been found to produce a great deal of damage to the bearing surfaces of the drum and to the regions of the drum adjacent the slot therein, and one of the objects of the present invention is to minimize such attendant shocks.

In addition to the mechanical shock problem discussed above, there is a thermal problem, due to the fact that the surface of the drum is usually heated to a temperature of about 1600 F. in the aforesaid furnace. The drum is carried on a drive shaft which is used for rotating the drum, and in order to preserve the life of the drive shaft in the furnace it is advantageous to resort to internal water cooling thereof. However, the drive shaft is located internally of the coiler drum in position to contact and chill the entering end of the hot strip being rolled. This introduces a metallurgical problem, because in effect any contact of the end of the strip being rolled with the water-cooled shaft results in a quenching action, and this can cause damage to the roll stand as can be visualized by noting that the roll stand at one instant will be working on a relatively hot, plastic section of the strip and in the next instant will encounter a quenched or hardened tail end section. Consequently, another object of the present invention is to so construct the coiler drum as to eliminate the possibility of the end of the strip being rolled striking a coiled member associated with the coiler drum.

Another significant thermal problem encountered in the structure under consideration has to do with the thermal differentials involved in view of the fact that inside areas of the coiler drum adjacent the shaft are relatively cold while the outer surface of the drum on which United States Patent 0 3,122,337 Patented Feb. 25, 1964 the strip will be wound is relatively hot. In accordance with the present invention the attendant thermal stressing, which is particularly acute in areas between the bearings of the drum and the outer surface of the drum, is minimized by constructing the intervening section in the form of a cone while minimizing thermal contact between the bearings and the water-cooled drive shaft, and so to do is another object of the present invention. An attendant advantage of this is that it is possible to in effect relocate the coiler drum bearings so that these can be disposed in cooler portions of the furnace.

Other and further objects of the present invention will be apparent from the following description and claims and are illustrated in the accompanying drawings which, by way of illustration, show a preferred embodiment of the present invention and the principles thereof and what is now considered to be the best mode contemplated for applying these principles. Other embodiments of the invention embodying the same or equivalent principles may be made as desired by those skilled in the art without departing from the present invention and the purview of the appended claims.

In the drawings:

FIG. 1 is a schematic representation of the type of rolling mill involved under the present invention;

FIG. 2 is a schematic representation of the type of furnace that is associated with such a rolling mill;

FIG. 3 is a plan view, partly broken away, of a coiler drum constructed under the present invention;

FIG. 4 is a plan view of the internal sleeve associated with the coiler drum illustrated in FIG. 3;

FIG. 5 is an end elevation taken substantially on the line 55 of FIG. 3; and

FIG. 6 is a sectional view, on an enlarged scale, taken on the line 6-6 of FIG. 3.

In FIGS. 1 and 2 there is illustrated schematically the general relationship of parts in a reversing strip rolling mill, such being inclusive of a roll stand 10, coiler drums 15, one each on opposite sides of the roll stand 10 and furnaces 16 in which the coiler drums are respectively located. The furnaces establish a temperature determined as that which is necessary to maintain the strip of steel sufiiciently hot to be rolled, and consequently the drums 15 are quite hot. The pass line for the strip being rolled is indicated by legend in FIG. 1, and the arrow 17 indicates that the oncoming free end of the steel strip, assumed to be coiled on the right-hand coiler drum 15, is to be guided into a slot in the left-hand coiler drum 15. In this connection, it may be noted that when it is determined that the free end of the oncoming strip being rolled has been properly guided into the receiving slot in the left-hand coiler drum 15, that drum will be rotated in a clockwise direction, as viewed in FIG. 1, at the required speed by a drive shaft 20, FIG. 2. This shaft is water-cooled.

When the strip has been coiled on the left-hand drum 15, the pass is reversed, and what was previously the trailing end of the strip (in a left-to-right-hand direction as viewed in FIG. 1) will become the leading end to be advanced to the roll stand and to be received in the receiving slot in the right-hand drum 15.

It will be recognized from the foregoing that the coiler drums 15 are subjected to considerable abuse, not only from a mechanical but also from a thermal standpoint. The entailed problems are considerably minimized under and in accordance with the present invention by the coiler drum construction illustrated in detail in FIGS. 3 to 6.

The coiler drum 15 of the present invention is inclusive of an outer generally cylindrical-shaped body which comprises a central member. in the form of a cylindrical body 22. For reasons to be explained in detail hereinafter, the coiler drum of the present invention is provided with end sections 24 and 25 which are generally in the form of truncated cones having the base or large diameter end, 26 in each instance, bevelled or sloped and disposed opposite a like bevelled surface 27 at the related end of the center section 22. When the three sections of the coiler drum have been assembled in this manner, weldments W1 and W2 are deposited in the annular V-shaped grooves 2647 to thereby ruggedly relate the end sections 24 and 25 to the center section 22.

It will be recognized, of course, that the narrow or small diameter ends of the end sections 24 and 25 are disposed outermost of the coiler drum assembly, and these ends of the cone sections of the coiler drum are provided with relatively thick axially inwardly directed annular Walls 39 affording internal bearing surfaces 35 which, as shown in FIG. 5, are square for a purpose to be explained hereinafter.

It will be realized from what has been described so far that the coiler drum under the present invention comprises three main parts 22, 24 and 25, aside from a separately fabricated insulator sleeve or tube to be described hereinafter. The three parts 22, 24 and 25 are separately cast and are welded together, and such construction makes it possible to provide for the various structural features herein described, noting that these structural features would be difficult if not impossible to obtain in a single one-piece casting having the contour and internal construction illustrated in the drawings and described in detail herein. In this connection, it has already been noted that the end cones 24 and 25 are cast with relatively thick inner walls 39 affording the squared bearing surfaces as 35. Additionally, each of the end cones 24 and 25 is cast to include arcuate, interrupted internal strengthening ribs R1, R2 and R3, FIG. 6, each of substantially 120 extent. Each such strengthening rib throughout the main extent thereof has a uniform inside diameter but at the ends thereof is rounded ed at RU to merge into the like rounded off end of the adjacent rib. This interruption permits the ribs R1, R2 and R3 to expand and contract as required.

As noted above, the coiler drum is provided with a slot to receive the oncoming end of a strip being rolled. Such slot is identified by reference character 40 in FIG. 3. The strip receiving slot 4i? extends the full length of the cylindrical portion 22 of the coiler drum and is sufficiently wide to allow free ingress of the leading end of the strip being rolled. In fact, it is desired that the slot be as Wide as possible so that there will be no doubt as to the free passage of the strip into the coiler drum. Such a wide slot might unduly weaken the coiler drum were it not for the strengthening ribs R1, R2 and R3, and in particular the rib R2, FIG. 6, which (on both ends 24 and 25) is substantially symmetrically oriented with respect to what would be the open end of the slot 40, as will be observed in FIG. 6. Thus, by extending the slot 40 entirely across the center section 22 to open at the opposite ends thereof adjacent the ribs R2, the latter take any beating from the free end of the strip entering the slot 40.

In order that the strip will be properly guided into the coiler drum to be clasped therein in a spool relationship, the cylindrical portion 22 of the coiler drum is cast to have a pair of lugs 43 and 44 internally thereof. These lugs in effect define the throat or gap of the receiving slot 40, and the opposed surfaces 43A and 44A thereof are flattened and are so sloped as to guide the advancing end of the steel strip. The internal surface of the cylinder 22 is provided with spaced arcuate wear-resisting skids or slides in the form of ribs 45 along which the entering end of the strip moves, and eventually the end of the strip slams up against a pair of stops 46 and 47 inside the drum.

Each such stop includes a pair of radially inwardly projecting ribs 48 cast integral with the drum section 22 and joined by a web 49 presenting a concave face, FIG. 6, engageable by the free end of the oncoming strip.

The coiler drum, as noted above, is secured for rotation with a drive shaft 2i that is cooled internally. The drive relationship in the present instance is afforded by coniplemental flattened surfaces of which the squared bearing surfaces 35 described above are a part. In securing the desired driving relationship, and for other reasons to be mentioned hereinafter, a sleeve 56, FIG. 4, is disposed within the coiler drum in a co-axial relationship, and this sleeve is adapted to surround the aforesaid water cooled shaft. As a consequence, the strip to be coiled will not contact the water cooled shaft, and at the same time the sleeve 54 is effective as an insulator between the water cooled shaft and adjacent sections or areas of the hot drum. It may be noted, however, that the guide surfaces 43A and 44A, FIG. 6, are oriented in an endeavor to prevent the strip from contacting the sleeve 59.

The sleeve 50, as shown in PEG. 4, comprises three main sections, namely, a center tube 51 and two separately cast end sections 52. The center tube and the end sections are of the same outside diameter, and adjacent annular edges are bevelled to enable these three parts to Y be joined together by weld deposits W and W5, FIG. 4.

The center section of the sleeve 5% is in the form of a substantially true cylinder throughout, but the outside surfaces of the end sections 52 are provided with square hubs or flanges 55, F568. 5 and 6, to engage complementally the square internal bearing surfaces 35 embodied in the cone ends of the coiler drum 12.

As shown in PEG. 4, the end members 52 of the sleeve 5'8 are provided with thickened walls, and these are provided with fiat internal surfaces 57, FIGS. 5 and 6, to be engageable with corresponding flat surfaces on the drive shaft 25). in this manner, the coiler drum is effectively keyed to the drive shaft 24}, and when the latter is rotated, the coiler drum will be rotated.

The coiler drum 12 as thus constructed is one wherein the three parts 22, 24 and 25 of the main body of the drum are themselves separately fabricated. This enables the center section 22 to be cast from a relatively expensive, but under the circumstances warranted, heatresistant alloy, whereas the truncated end sections can be separately cast from a relatively less expensive alloy since these are not subjected to temperatures as high as those to which the center section of the coiler drum will be exposed. Thus, referring to FIG. 2, the end sections, and especially the bearings, are nearer the side walls SW of the furnace where the heat is not so intense.

Such separately fabricated parts also enable each part to be cast with internal configurations that would be difiicult if not impossible to achieve in a one-piece casting having the same contours. Thus, the truncated end cones can be cast to include the sloped side walls 24W, FIG. 3, which are relatively thin in comparison to the thickened and sturdy hubs 3% which afford the internal bearing surfaces 35. Additionally, the end sections of the coiler drum can be cast to include the discontinuous strengthening ribs R1, R2 and R3, the rib R2 in particular serving to strengthen the areas of the coiler drum that are immediately adjacent the ends of the slot 4d. The other two ribs R1 and R3 primarily balance the rib R2, and the discontinuity between the ribs allows for expansion and contraction due to the thermal differentials that are likely to be encountered.

Considering the center section 22 in its entirety, the internal surface thereof is characterized by the flat guide surfaces 43A and 44A which serve to direct the oncoming end of the strip on to the skids 45 which in turn direct the free end of the strip toward the radial inwardly projecting stops 46 and 4-7. Thus, it will be seen that the separate fabrication contemplated in the present instance permits numerous functional advantages to be achieved.

The fact that the coiler drum is constructed to include the separately fabricated sleeve 5t), which will surround the aforesaid drive shaft, protects the strip being rolled from contacting. the cold drive shaft. Additionally, by

truncating or sloping the end sections 24 and 2-5, the presence of a vertically oriented plate section between the outer cylindrical surface of the drum and the internal bearing surface 35 is avoided, and it may be noted that in this intervening area occurs the most severe thermal stressing due to the large temperature differential involved between the hot outer surface of the drum and the cooler bearing surface that are nearer the watercooled drive shaft 20. The cone shape utilized will absorb Lie thermal stressing more flexibly in comparison to a straight, vertical section, and additionally, the truncated cone is mechanically more rigid.

Hence, while I have illustrated and described a preferred embodiment of my invention it is to be understood that this is capable of variation and modification, and I therefore do not wish to be limited to the precise details set forth, but desire to avail myself of such changes and alterations as fall within the purview of the following Claims.

I claim:

1. A coiler drum for use in a reversing strip rolling mill com rising an outer cylinder-like body of predetermined outside diameter, said body having secured thereto end sections in the form of truncated cones with the narrow ends outermost of said body, the bases of said end sections having substantially the outside diameter of said body, internal bearings presented by said end sections at the narrow ends thereof, whereby said bearings are spaced a substantial distance outward of the ends of said body, said body being slotted to receive the end of a steel strip in the process of being rolled, and a sleeve disposed within said bearings and adapted to surround concentrically a drive shaft for rotating the drum.

2. A coiler drum for use in a reversing strip rolling mill comprising an outer body including a center cylinder of substantially uniform outside diameter throughout, said cylinder being slotted axially to receive an end of a steel strip in the process of being rolled, said cylinder having welded to each end thereof an end section in the form or a truncated cone with the narrow end thereof outermost of the coiler drum, the bases of said end sections having substantially the outside diameter of said cylinder, each of said sections having a fiat bearing surface formed on the inside thereof at the narrow ends thereof whereby said bearings are spaced substantially outward of the ends of said body, and a sleeve disposed within said center cylinder and having end surfaces complementally engaging the bearing surfaces of said end sections.

3. A coiler drum for use in a reversing strip rolling mill comprising an outer cylinder-like body havingtapered end sections in the form of separately cast truncated cones secured thereto with the narrow ends outermost, the bases of said end sections being of substantially the same outside diameter as said body, said end sections having internal bearings at the narrow ends thereof whereby said bearings are spaced a substantial distance outward of the ends of said body, said body being slotted to receive the end of a steel strip in the process of being rolled, and a sleeve cast of a heat-resistant alloy disposed Within said body and having spaced portions supported by said internal bearings.

4. A coiler drum for use in a reversing strip rolling mill comprising an outer body including a center cylinder of substantially uniform outside diameter tluoughout, said cylinder being slotted to receive an end of a steel strip in the process of being rolled, said cylinder having Welded to each end thereof an end section in the form of a truncated cone with the narrow end thereof outermost of the coiler drum, the bases of said end sections being of substantially the same outside diameter as said cylinder, each of said ac tions having a squared bearing formed on the inside surface thereof immediately adjacent the narrow end thereof whereby said bearings are spaced a substantial distance outward of the ends of said cylinder, and a sleeve cast of a heat-resistant alloy disposed within said center cylinder and having squared ends complementally fitted in said squared bearings.

5. A coiler drum for use in a reversing strip rolling mill comprising an outer cylindenlike body having a center section substantially a true cylinder, said body having secured thereto end sections in the form of truncated cones with the narrow ends outermost, the bases of said end sections having substantially tle outside diameter as said body, said center section being slotted throughout the length thereof between the end sections to receive the end of a strip to be rolled, a sleeve disposed within and supported by said body and adapted to surround concentrically a drive shaft for rotating the drum, and said end sections being formed at the narrow ends thereof with internal bearings for a support shaft whereby said bearings are spaced a substantial distance outward of the ends of said body.

References Cited in the file of this patent UNITED STATES PATENTS 

1. A COILER DRUM FOR USE IN A REVERSING STRIP ROLLING MILL COMPRISING AN OUTER CYLINDER-LIKE BODY OF PREDETERMINED OUTSIDE DIAMETER, SAID BODY HAVING SECURED THERETO END SECTIONS IN THE FORM OF TRUNCATED CONES WITH THE NARROW ENDS OUTERMOST OF SAID BODY, THE BASES OF SAID END SECTIONS HAVING SUBSTANTIALLY THE OUTSIDE DIAMETER OF SAID BODY, INTERNAL BEARINGS PRESENTED BY SAID END SECTIONS AT THE NARROW ENDS THEREOF, WHEREBY SAID BEARINGS ARE SPACED A SUBSTANTIAL DISTANCE OUTWARD OF THE ENDS OF SAID BODY, SAID BODY BEING SLOTTED TO RECEIVE THE END OF A STEEL STRIP IN THE PROCESS OF BEING ROLLED, AND A SLEEVE DISPOSED WITHIN SAID BEARINGS AND ADAPTED TO SURROUND CONCENTRICALLY A DRIVE SHAFT FOR ROTATING THE DRUM. 